Quick disconnect tube coupling

ABSTRACT

A tube coupling having a male body, a female body for receiving at least a portion of the male body and at least one peripheral member made from a relatively compressible plastic material molded into a groove within either the relatively rigid male or female body. The peripheral member is disposed to become compresed against a surface of the mating body to form a liquid seal. At least two peripheral members disposed in grooves in a tubular shaped end portion of the male body are made of a compressible plastic and serve as liquid sealing and locking means. The female body comprises a receiving end portion with a tapered interior adapted to receive the male tubular end portion. As the tubular end portion is inserted into the receiving end portion, one of the peripheral members engages the tapered interior surface and becomes compressed there against as the tubular end portion is further inserted. As the tubular end portion is fully inserted a second peripheral member seats itself in a groove in the interior surface of the receiving end portion acting to lock the male and female bodies together. The relatively compressible peripheral members are formed in grooves in the relatively rigid male or female body by insert molding or by simultaneous injection molding of two dissimilar plastics.

This is a continuation of application Ser. No. 573,545 filed on Jan. 25,1984, abandoned.

BACKGROUND OF THE INVENTION

This invention relates to an improved tube coupling for connecting thetwo tube lengths which coupling provides a locking engagement, aneffective liquid seal when the tube lengths are connected and a quickdisconnect capability. More particularly, the invention relates to tubecouplings for medical use although it is not limited to medicalapplications.

In the prior art many tube couplings are shown comprising a male bodyand a female body and which provide for a positive locking capabilitywhen joining the male and female bodies together. For example, seefingers 34, latch blades 36 and groove 38 in U.S. Pat. No. 3,245,703;see arms 32 and 34 with latch projection 36 and annular shoulder 30 inU.S. Pat. No. 3,394,954; see molded plastic latch 154 in FIG. 2 of U.S.Pat. No. 3,602,009; see the coupling element of FIG. 5 and the rear edgeof collar 15 in U.S. Pat. No. 3,603,621; see the inwardly projectingflanges 18 and recessed collar member 21 in U.S. Pat. No. 4,123,091; andthe intermediate ring 100 and rim 58 of published UK Patent ApplicationNo. GB 2,092,690 A. The various locking mechanisms described in theabove-mentioned patent applications are released so that the couplingscan be disconnected by either applying a squeezing type pressure to aportion of the latch or locking mechanism (U.S. Pat. Nos. 3,245,703;3,394,954; 3,602,009; and the UK Patent Application), or by turning,twisting or rotating various portions of the couplers relative to oneanother (U.S. Pat. Nos. 3,603,621 and 4,123,091).

To provide a liquid seal various approaches are used in the prior art,but one of the most common comprises placement of separatelymanufactured O-rings in annular grooves surrounding a portion of themale body which portion is inserted in a corresponding cavity of thefemale body. In particular, see the pair of O-rings 13 and 28 in U.S.Pat. Nos. 4,123,091 and 3,394,954, respectively. O-rings generallyfunction by having a larger outer diameter when placed in the grooves onthe male member than the outer diameter of the corresponding portion ofthe male member. The O-rings are made of a compressible material such asrubber and when inserted in the female cavity, they are compressedagainst the relatively smooth interior surface thereof to form a liquidseal.

As described above the various prior art devices require separateapproaches for providing a locking mechanism and a liquid seal. Further,the prior art devices require some form of separate action to remove thelocking action of the locking device; and require the inclusion ofseparately manufactured O-rings in the assembly of the tube coupling.

SUMMARY OF THE INVENTION

An object of the present invention is to provide an improved tubecoupling device.

A further object of the present invention is to provide a simplifiedtube coupling with a quick disconnect capability.

Still a further object is to provide the above mentioned tube couplingwhich tube coupling provides an effective liquid seal.

Another object of the present invention is to provide the abovementioned tube coupling having a positive locking action.

Another object of the present invention is to provide the abovementioned tube coupling wherein the means for providing a liquid sealand locking action is integral with either the male or female portion ofthe coupling.

A further object of the present invention is to provide the abovementioned tube coupling wherein the means for sealing and locking doesnot interfere in the quick disconnect capability of the tube coupling.

The present invention tube coupling comprises a male body and a femalebody. At least one peripheral member made from a relatively compressibleplastic material is disposed within a groove of one of the bodies. Theperipheral member becomes compressed against the surface of theremaining one of the bodies when the male and female bodies are matinglyengaged. In a preferred embodiment, the at least one peripheral memberis molded within a groove surrounding a hollow plug end portion of themale body. Where the male body is further made of a synthetic plasticmaterial formed in a mold it further comprises an alignment means forproperly aligning the male body after forming thereof to accept formingof the peripheral member in the groove by subsequent insert molding.

The present invention tube coupling further comprises a male body, afemale body and a locking and a liquid sealing means. The locking andsealing means comprises at least a pair of spaced apart peripheralmembers which are disposed within grooves in one of the bodies, a firstone of the peripheral members disposed to be compressed against thesurface of the remaining body to form a liquid seal therewith. Thesecond one of the peripheral members fits within a groove located withinthe mating body when the male and female bodies are matingly engaged.

In one embodiment of the invention, a pair of spaced apart peripheralmembers are disposed within grooves surrounding a hollow plug endportion of the male body. One of the peripheral members is disposed tobe compressed against the interior surface of a receiving end portion ofthe female body to provide a liquid seal while the other peripheralmember is disposed to fit within a groove located within the interiorsurface of the receiving end portion of the female body. Alternatively,the peripheral members could be disposed within the interior surface ofthe receiving end portion and an annular groove for receiving one of theperipheral members surrounds the plug end portion of the male body.

In the preferred embodiment of the present invention, the peripheralmember which provides the primary liquid seal with the interior surfaceof the mating body has a substantially rectangular cross section, whilethe peripheral member providing a substantial locking action has acircular cross section.

In one embodiment of the present invention, the receiving end portion ofthe female body is tapered.

Preferably, the locking and sealing means are made of a an elastomericthermoplastic resin material and is integrally formed with either themale or female body made from a high density polyethylene orpolypropylene.

Other features and advantages of the invention will become apparent fromthe following description read in conjunction with the attached drawingsin which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a longitudinal view of the male and female bodies of thepresent invention, the female body being shown in cross section and themale body being shown partially in cross section.

FIG. 2 is an enlarged cross-sectional view of a portion of the male bodyof FIG. 1 taken along the lines and arrows 2.

FIG. 3 is a longitudinal view of alternate embodiments of a portion ofthe male and female bodies of FIG. 1.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring now to FIG. 1, the male and female bodies designated generally10 and 12 respectively are shown seperated but located along a commonlongitudinal axis. Female body 10 is shown in cross section andcomprises a tubular shaped receiving end portion 20 which defines aninterior region 22. Opposite from receiving end portion 20 andintegrally connected therewith is a tube connecting portion 24 with atapered saw tooth shaped outer surface. The tube connecting portion 24is adapted to be inserted into a length of tube and the tapered sawtooth outer surface provides a gradually increasing frictional fitbetween the female body and the length of tube while preventingexcessive distortion and deformation of the tubing. The entry portion ofthe length of tube is in fairly continuous contact with the saw toothouter surface. The hollow interior 26 of the tube connecting portion 24communicates with both the interior of the length of tube and theinterior region 22.

In FIG. 1, the interior surface of the receiving end portion 20 istapered, that is, the cross-sectional diameter of the interior region 22at the open end of the receiving end portion 20 is larger than theparallel and spaced apart cross-sectional diameter of the interiorregion 22 defined at the rim 28 of the receiving end portion 20, and thewall 30 of the interior surface slopes linearly from the cross-sectionaldiameter at the open end to inner cross-sectional diameter at the rim28. The interior surface of the receiving end portion 20 furthercomprises an annular groove 32.

Male body 12 comprises a tube connecting portion 40 similar in shape andpurpose to the tube connecting portion 24 of the female body 10.However, it further comprises a pair of ledges only one of which 42 isshown which ledges project inwardly into the hollow interior 44 of thetube connecting portion 40. The ledges 42 are in the preferredembodiment located on a common diameter of the tube connecting portion40.

Male body 12 further comprises a tubular shaped plug end portion 50intergrally formed with the tube connecting portion 40 and adapted to beinserted into the interior region 22 of the receiving end portion 20.The interior of the plug end portion 50 communicates with the hollowinterior 44 of the tube connecting portion 40 which in turn communicateswith the interior of a length of tube when the tube connecting body 40is inserted therein.

It should be appreciated that the term "tubular shaped" as used todescribe the receiving end portion and the plug end portion includeshollow cylinders or bodies of various shaped cross sections includingcircular, rectangular and square cross sections.

The outer diameter (OD) of the generally cylindrically shaped plug endportion is uniform throughout its length except at grooves 52 and 54,shown in FIG. 2, and except for the annular ridge 56. The outer diameterof the plug end portion 50 is slightly less than the cross-sectionaldiameter of the interior region 22 at rim 28. For example, the outerdiameter of the plug end portion in the preferred embodiment isapproximately 0.359" while the cross-sectional diameter of the interiorregion 22 at the open end of the receiving end portion is approximately0.398" and the cross-sectional diameter at rim 28 approximately 0.370".

The longitudinal length of the plug end portion from the open end 58 tothe annular ridge 56 is substantially equal to the longitudinal lengthof the interior region 22 from the inner cross-sectional diameter at rim28 to the outer edge of the receiving end portion 20. Annular ridge 56contacts the outer surface 34 of the receiving end portion 20 as theopen end 58 of the plug end portion 50 contacts the rim 28.

FIG. 2 is an enlarged cross section of a portion of the male body inFIG. 1 taken along the lines and arrows 2 in FIG. 1. The plug endportion 50 includes the annular rectangularly shaped grooves 52 and 54.In the preferred embodiment, the grooves are filled by inset moldingwith an elastomeric thermoplastic resin material which forms a pair ofperipheral members 60 and 62. Ledges 42 assist in aligning the male bodyduring the insert molding step. Inspection of FIGS. 1 and 2 show thatthe OD of both peripheral members 60 and 62 exceeds the OD of the plugend portion 50, with the peripheral member 62 having a slightly largerOD than the peripheral member 60. In the preferred embodiment, the OD ofthe peripheral member 60 is 0.383" and the OD of the peripheral member62 is 0.391".

While the preferred material for the peripheral members 60 and 62 is anelastomeric thermoplastic resin, the preferred material for the malebody is any rigid plastic material suitable for the intended applicationof the coupling. In medical applications a suitable rigid plasticmaterial comprises a high density polyethylene or polypropylene.

An alternate method for forming the peripheral members 60 and 62 is asfollows: the male body is formed by injection molding and, before theplastic material of which the male body is made sets, the peripheralmembers are formed by injection molding of an elastomeric thermoplasticresin. The plastic resin melt fills the male body mold in the grooves 52and 54 and mixes with the plastic material of which the male body iscomposed at the mold interface surrounding the grooves 52 and 54. Herethe primary melt of the male body intimately coalesces with thesecondary melt of the thermoplastic resin to form a chemical andmechanical bond between the two materials. The injection molding stepfor both the male body and the peripheral members may take placesimultaneously where an appropriate mold for the male body including theperipheral members is fabricated and both primary and secondary moldinjection stations are established. Alternatively, the injection moldingstep of the male body occurs first followed soon after by the injectionmolding step for the peripheral members, the latter injection moldingstep occuring before the melt composition of the male body has set. Asuitable method of performing the injection molding process describedabove is described further in U.S. Pat. No. 3,950,483.

Referring once again to FIG. 1, as the male body is inserted into thefemale body, the peripheral member 60 comes in contact with the wall 30and is gradually compressed against the wall 30 as the male body isfully inserted. Deformation of the peripheral member 60 against the wall30 forms a liquid seal. As the front edge 58 of the male body approachesthe rim 28, the peripheral member 62 begins to seat itself withinannular groove 32. The maximum dimension of groove 32 is approximatelyequal to the OD of the peripheral member 62. The curved shape of theperipheral member 62 aids in seating member 62 within annular groove 32.Positioning of member 62 in groove 32 acts to lock the female and malebodies together. Also, member 62 seated in groove 32 acts as a furtherliquid seal. The peripheral member 62 in combination with a tightfitting groove 32 acts as a liquid sealing and locking means.

Hence, bodies 10 and 12 are quickly connected together in one pushingaction applied along their common longitudinal axis. All that isrequired to disconnect the bodies is a pulling force of each body awayfrom the other again along their common longitudinal axis. A sufficientforce must be applied to overcome the seating of peripheral member 62 ingroove 32. Since member 62 is compressible, it will eventually give wayand leave groove 32 as the pulling force increases. However, the lockingforce is sufficient that under normal use the connector will notseparate. Since the peripheral members 60 and 62 are preferably anelastomeric material they return to their original shape after thebodies 10 and 12 are disconnected.

The tapered interior surface assists in bringing the male and femalebodies into mating engagement. The frictional force encountered withdeformation of member 60 as it slides along wall 30 also aids in lockingthe bodies together. Also, the tapered interior aids in seatingperipheral member 62 into groove 32.

With the tube coupling of the present invention, there is no latch orlocking mechanism requiring a separate action to disconnect the male andfemale bodies such as a squeeze or twisting action. The peripheralmembers which provide a seal also act to create a locking action. Thisis possible because the peripheral members 60 and 62 are a compressiblematerial which is formed integral with the rigid material of the malemember. In the case where the peripheral members are formed by injectionmolding before the male body melt composition has set, the chemical andmechanical bond formed thereby acts to avoid separation of theperipheral members 60 and 62 from the grooves 52 and 54 respectively.

FIG. 3 is an alternate embodiment 310 and 312 of a portion of the maleand female bodies 10 and 12, respectively, of FIG. 1. The bodies 310 and312 are equipped with tube connecting portions identical to tubeconnecting portions 24 and 40, respectively, and they accordingly arenot shown in FIG. 3. Female body 310 comprises a receiving end portion320 and a male body 312 comprises a plug end portion 350. However,instead of forming peripheral members in grooves on the external surfaceof the plug end portion 350, peripheral members 360 and 362 are formedwithin grooves in the interior surface of wall 330 of receiving endportion 320 by insert molding or simultaneous injection molding asdescribed above. The cross-sectional diameter of the interior region 322of the receiving end portion 320 is generally constant throughout itslength from the interior rim 28 to the open end of the receiving endportion.

Spigot end portion 350 further comprises an annular groove 32 and anannular ridge 356. The cross-sectional diameter of the plug end portion350 is generally constant throughout its length except for the annulargroove 332. Also, the cross-sectional diameter of plug end portion 350is generally less than then the cross-sectional area of the interiorregion 322. However, the inner diameter of both the peripheral members360 and 362 are smaller than both the cross-sectional diameters of theinterior region 322 and the plug end portion 350. As plug end portion350 is inserted into the receiving end portion 320 the exterior surfaceof the plug end portion 350 frictionally contacts the peripheral members360 and 362. The peripheral members 360 and 362 are made of acompressible material such as an elastomeric thermoplastic resin and asthe plug end portion is inserted further into the interior region 322they make a liquid seal with the exterior surface of the plug endportion 350. As the front end 358 of the plug end portion contacts theannular rim 328 the peripheral member 362 seats itself within theannular groove 332 of the plug end portion 350. At the same time annularridge 356 engages the outer edge 334 of the receiving end portion 320.

The peripheral member 360 in the preferred embodiment has a rectangularcross section while the peripheral member 362 has a circular crosssection. The circular cross section of peripheral member 362 aids inseating the peripheral member 362 and the annular groove 332.

The peripheral members 360 and 362 interacting with the plug end portion350 act to create a liquid seal and, a positive locking action withoutinterferring with a quick disconnect capability of the tube coupler.

While certain specific embodiments of the invention have beenillustrated and described in detail herein, it is obvious that manymodifications thereof may be made without departing from the spirit andscope of the invention.

What is claimed:
 1. A quick disconnect coupling for connecting to twotube lengths to be coupled comprising:a male body having an elongatedtubular shaped plug end portion; a female body having an elongatedtubular shaped receiving end portion of substantially the same length assaid plug end portion for receiving said plug end portion for matingengagement therewith; and at least a pair of spaced apart peripheralmembers made from a relatively compressible plastic material and moldedwithin grooves in the tubular shaped portion of one of said bodies, afirst one of said at least a pair of peripheral members disposed to becompressed against a surface of the tubular shaped portion of theremaining body and a second one of said at least a pair disposed to fitwithin a groove within the tubular shaped portion of said remaining bodywhen said male and female bodies are matingly engaged, said first andsecond peripheral members cooperating together to form a liquid seal andlocking engagement between said male and female bodies, the lengths ofsaid elongated end portions and the spacing of said at least a pair ofspaced apart peripheral members being such that said at least a pair ofperipheral members act as a guide in preventing relative tilting of saidmale and female bodies with respect to their common longitudinal axiswhen coupled whereby said liquid seal is preserved.
 2. The coupling ofclaim 1 wherein said male and female bodies comprise a relatively rigidsynthetic plastic material and said at least a pair of peripheralmembers comprise an elastomeric thermoplastic resin material.
 3. Aquick-disconnect coupling for connecting to two tube lengths to becoupled comprising:a male body having an elongated tubular shaped plugend portion; a female body having an elongated tubular shaped receivingend portion for receiving said plug end portion therewithin in matingengagement; and at least a pair of spaced apart peripheral members madefrom a relatively compressible plastic material and molded withingrooves surrounding said plug end portion, a first one of said at leasta pair disposed to be compressed against the interior surface of saidreceiving end portion, and a second one of said at least a pair disposedto fit within a groove within said interior surface when said plug endportion matingly engages said receiving end portion, said first andsecond peripheral members cooperating together to form a liquid seal andlocking engagement between said male and female bodies, the lengths ofsaid elongated end portions and the spacing of said at least a pair ofspaced apart peripheral members being such that said at least a pair ofperipheral members act as a guide in preventing relative tilting of saidmale and female bodies with respect to their common longitudinal axiswhen coupled whereby said liquid seal is preserved.
 4. The coupling ofclaim 3 wherein said receiving end portion comprises a tapered interiorsurface, said first one of said at least a pair of peripheral membershaving an outside diameter less than said second one and disposed onsaid plug end portion to engage said tapered interior surface beforesaid second peripheral member as said male and female bodies areengaged.
 5. The coupling of claim 4 wherein said male and female bodiescomprise relatively rigid synthetic plastic material and said at least apair of peripheral members comprise an elastomeric thermoplastic resinmaterial.